Key-operated electrical switch with a movable insulator having detents



March 1966 w. N. SCHINK ETAL 3,

KEY-OPERATED ELECTRICAL SWITCH WITH A MOVABLE INSULATOR HAVING DETENTS 2 Sheets-Sheet 2 Filed Dec. 3, 1962 United States Patent 3,239,615 KEY-QPERATED ELECTRICAL SWITCH WITH A MOVABLE INSULATQR HAVING DETENTS William N. Schink, Crystal Lake, and William J. Schaad,

Glenview, IIL, assignors to Indak Manufacturing Corp.,

Northbroolr, 111., a corporation of Illinois Filed Dec. 3, 1962, Ser. No. 241,835 6 Claims. (Cl. 28044) This invention relates to electrical switches and pertains particularly to switches which are key operated. Such switches are commonly employed in the ignition circuits of internal combustion engines, and for many other purposes.

One object of the present invention is to provide a keyoperated switch which is extremely compact and low in cost, yet is positive and dependable in operation.

A further object is to provide a new and improved switch having a movable insulator which not only carries the contactor of the switch but also provides integral detent elements which cooperate with grooves or other detent means on the case of the switch.

Another object is to provide a new and improved switch of the foregoing character in which the inherent resilience of the insulator is employed to bias the detent elements on the insulator into engagement with the detent recesses on the case.

A further object is to provide such a new and improved switch in which the insulator is effectively U-shaped, with a pair of longitudinal legs which are flexible and resilient for biasing the detent elements against the case.

It is another object to provide a new and improved switch of the foregoing character in which the legs are defined by longitudinal slots extending part way along the insulator.

A further object is to provide a new and improved switch in which the insulator engages and retains the tumbler or tumblers in the rotatable carriage of the switch.

Further objects and advantages of the present invention will appear from the following description, taken with the accompanying drawings, in which:

FIG. 1 is a front elevational view of a key-operated electrical switch to be described as an illustrative embodiment of the present invention, certain parts of the switch being broken away for clarity of illustration.

FIG. 2 is a side elevational view of the switch.

FIG. 3 is a rear elevational view of the switch.

FIG. 4 is a central longitudinal section of the switch.

FIG. 5 is a view similar to FIG. 4 but showing the position of the switch after the operating key has been inserted.

FIG. 6 is a longitudinal section, taken generally along a line 6-6 in FIG. 5.

FIG. 7 is a cross section taken through the tumbler mechanism of the switch, generally along the line 77 in FIG. 4.

FIG. 8 is a cross section, taken generally along the line 88 in FIG. 4, and showing the detents on the insulator.

FIG. 9 is a cross-sectional view, taken generally along the line 99 in FIG. 4.

FIG. 10 is a section similar to FIG. 7 but showing the position of the switch after the operating key has been inserted, the view being taken generally along the line 10-10 in FIG. 5.

FIG. 11 is a sectional view looking forwardly, generally along the line 1l11 in FIG. 4.

FIG. 12 is a sectional view looking rearwardly, generally along the line 12-12 in FIG. 4.

FIG. 13 is a view similar to FIG. 10 but showing the position of the switch after the operating key has been rotated through approximately degrees.

FIG. 14 is a perspective view showing the contactor of the switch.

FIG. 15 is a perspective view showing the movable insulator of the switch.

FIG. 16 is a perspective view showing the tumbler.

FIG. 17 is a perspective view showing the Z-shaped tumbler spring.

FIG. 18 is a perspective view showing the rotatable carriage of the switch.

As already indicated, the drawings illustrate a keyoperated electrical switch 20 which is of the cylinder type, useful for automotive ignition switching and many other applications. Thus, the switch 20 comprises a generally cylindrical case 22 formed at its front end with a mounting flange 24. Behind the flange 24, the case 20 has a threaded outer portion 26 for receiving any suitable nut, not shown, whereby the switch may be mounted in a hole formed in a panel, bracket or the like.

A generally cylindrical carriage 23 is rotatably mounted within the case 20. It will be seen that a longitudinal key slot 30 is formed in the carriage 28. A key 32 is adapted to be received in the slot 30.

The lock 20 may be provided with one or more tumblers adapted to prevent rotation of the carriage 28 until the proper key has been inserted into the slot 30. In this case, a single tumbler 34 is slidably mounted in a transverse tumbler opening or slot 36 formed in the rotatable carriage. When the key 32 is inserted, the ends of the tumbler are flush with the outside of the rotatable carriage 28. When the key is withdrawn, the tumbler 34 is moved into a locking groove or slot 38 formed in the case 22. As shown to advantage in FIG. 4, a Z-shaped tumbler spring 40, preferably made of spring wire, is connected between the rotatable carriage 28 and the tumbler to bias the tumbler along the tumbler slot 36 so that the tumbler tends to enter the locking slot 38. As shown to advantage in FIG. 10, the tumbler spring 40 is mounted in a recess 42 which is formed in the rotatable carriage on one side of the tumbler slot 36. The tumbler spring 40 is compressed between one side of the recess 42 and a tab or projection 44 on one side of the tumbler 34. The key 32 is adapted to be inserted through a slot 46 extending through the tumbler 34. Of course, the slot 46 is aligned with the key slot 36 in the carriage 28.

It will be seen from a comparison of FIGS. 10 and 13 that the carriage 28 is rotatable through approximately 90 degrees. Such rotation is limited by a segmental flange 50 (FIG. 1) formed on the front end of the carriage 28. The flange St) is movable in a segmental groove 52 and is engageable with a segmental member 54 on the case 22. In the initial open position of the switch, one end of the segmental flange 50 engages a stop shoulder 56 at one end of the stationary member 54. When the rotatable carriage 28 has been turned through 90 degrees in a clockwise direction, the other end of the flange 50 engages a stop shoulder 58 on the other end of the stationary member 54.

In this case, the rotatable carriage 28 is retained within the case 22 by means of a sheet metal ring or collar 60 which covers the mounting flange 24 and the front end of the case 22. The collar 60 may be secured to the case 22 by means of a flange 62 which is bent or spun behind the mounting flange 24.

In the illustrated switch, an insulator 66 is slidably mounted in a slot 68 formed in the rear portion of the rotatable carriage 28. The insulator slot 68 may be a continuation of the slot 36 which receives the tumbler 34. The insulator 66 may be generally in the form of a block and may be made of a suitable plastic or other insulating material.

As shown to advantage in FIG. 15, the sides of the insulator 66 may be formed with ribs or raised guides 70 and 72. Grooves 74 and 76 may be formed in the rotatable carriage 28 on the sides of the slot 68 to receive the ribs 70 and 72 so as to prevent the insulator 66 from shifting laterally in the slot 68, while providing for movement of the insulator 66 in the slot 68 in a direction parallel to the longitudinal axis of the carriage 28. It will be seen that the front portion of the rib 72 is omitted or cut away to provide room for the Z-shaped tumbler spring 40. The groove 76 in the rotatable carriage 28 may constitute an extension of the recess 42 for the tumbler spring 40.

The tumbler slot 36 and the insulator slot 68 are formed in front and rear portions 80 and 82 of the rotatable carriage 28. It will be seen that the rear portion 82 is reduced in diameter relative to the front portion 80. The carriage 28 is rotatable in stepped bore 84 formed in the case 22. The bore 34 has a front portion 86 of relatively large diameter in which the larger front portion 80 of the carriage 28 is received. The bore 84 also has a reduced rear portion 88 in which the reduced rear portion 82 of the carriage 28 is received. An annular shoulder 90 is formed between'the front and rear portions 86 and 88 of the bore 84. To engage the shoulder 90, a pair of flanges 92 may be formed on the insulator 66. The engagement of the flanges 92 with the shoulder 90 restrains the rearward movement of the insulator 66.

It will be apparent from FIGS. 4-6 that the rear side of the tumbler is slidably engaged with the front side of the insulator 66. Thus, the insulator 66 retains the tumbler 34 in the tumbler slot 36 against rearward movement, while permitting movement of the tumbler 34 in a direction transverse to the longitudinal axis of the carriage 28.

The front portion of the insulator 66 may be formed with a key slot 96 which is adapted to receive the end portion of the key 3-2. The key slot 96 in the insulator is aligned with the similar slot 46 in the tumbler 34. The illustrated slot 96 extends only part way through the insulator 66.

One important purpose of the insulator 66 is to support a movable contactor 100 which is adapted to engage a plurality of contacts or points 101 and 102 mounted on an insulating terminal board or wall 104. It will be seen from FIGS. 4 and that the insulating board 104 closes the rear end of the case. An enlarged counter bore or recess 106 may be formed in the rear portion of the case 22 to receive the board 104. In this case, the board 104 is retained by a flange 108 which is turned or bent inwardly from the case 22 behind the board 104.

The contacts 101 and 102 may be formed on the front ends of rivets 111 and 112 extending through the terminal board 104. Suitable terminals 114 and 116 may be connected to the rivets 111 and 112. It will be seen that the contact points 101 and 102 project forwardly beyond the front surface of the terminal board 104, for engagement by the contactor 100.

The illustrated contactor 100, as shown to advantage in FIG. 14, comprises a generally rectangular bar portion 120 formed with a pair of legs 122 extending perpendicular to the ends of the bar portion 120. In this case, grooves 124 are formed in the narrower sides of the insulator 66 for slidably receiving the legs 122, so as to guide the contactor 100 for movement along the longitudinal axis of the rotatable carriage 28. The bar portion 120 of the contractor 100 may be perpendicular to the rotary axis of the rotatable carriage 28.

Initially, the contactor 100 is out of engagement with the contact points 101 and 102. The initial direction of the bar portion 120 is perpendicular to a line extending between the contact points 101 and 102. The bar portion 120 is formed with a pair of notches 126 to avoid initial 4 engagement between the contactor and the contact points 101 and 102.

The illustrated contactor is biased rearwardly by a spring 128 which is preferably of the coiled compression type and is disposed between the insulator 66 and the bar portion of the contactor 100. In this case, the spring 128 is mounted in a bore or recess 130 formed in the rear end of the insulator 66. In addition to biasing the contactor 100 rearwardly, the spring 128 biases the insulator 66 forwardly so as to maintain the insulator in slidable engagement with the tumbler 34.

In its initial position, shown in FIG. 11, the contactor 100 engages a pair of projections or knob-s 132 which are formed on the front side of the insulating bore 104. The knobs 132 are formed on bosses or steps 134 which project forwardly from the front surface of the terminal board 104 on which the contact points 101 and 102 are mounted. The knobs 132 and the steps 134 prevent the contactor 100 from engaging the contact points 101 and 102 until the contactor has been rotated through approximately 90 degrees to bring the bar portion 120 of the contactor 101 into alignment with the contact points.

The rear surface of the contactor 100 is formed with a pair of grooves or recesses 136 for receiving the contact points 101 and 102. The grooves 136 are also adapted to receive the knobs 132 when the comtactor is in its initial position.

In accordance with one feature of the present invention, the insulator 66 is arranged to serve as a detent member, in addition to providing an insulating support for the contactor 100. Thus, one or more detent projections 140 are formed on the insulator 66, preferably adjacent the flanges 92. The detent projections 140 extend radially beyond the narrower sides of the insulator 66. Two sets of detent notches or grooves 142 and 144 are formed in the inside of the case 22 to receive the detent projections 140. The detent recesses 142 and 144 may be formed in the reduced bore 88 just behind the shoulder 90. In this case, the detent projections 140 are received in the detent grooves 142 when the insulator 66 is in its initial position, as shown in FIG. 8. When the carriage 2S and the insulator 66 have been rotated through 90 degrees, the detent projections 140 are received in the grooves 144.

The construction of the insulator 66 is such that the inherent resilience of the insulator is employed to bias the detent projections 140 outwardly for reception in the detent grooves 142 and 144. To this end, the insulator 66 is preferably formed with a pair of slots 148 extending part way along the longitudinal dimension of of the insulator. The slots 148 effectively divide the insulator 66 into a pair of legs 1S0 extending longitudinally from a connecting portion 152 at the rear end of the insulator 66. The slots 148 are formed in the front portion of the insulator 66. It will be noted that the legs 150 and the connecting portion 152 form a generally U-shaped structure. The provision of the slots 148 enables the legs 150 to flex inwardly and outwardly to a considerable extent so as to provide for the movement of the detent projections 140 out of the detent notches 142 and 144. The resilience of the legs 150 and the connecting portion 152 biases the detent projections 140 outwardly so that they tend to be retained in the detent notches 142 and 144.

When the insulator 66 is in its initial position, as shown in FIG. 8, the detent projections 140 are received in the detent notches 142. When the insulator 66 is rotated along with the carriage 28, the insulator 66 must be turned with sufiicient force to flex the legs 150 inwardly, so as to permit the detent projections 140 to move out of the detent notches 142. After the carriage 28 and the insulator 66 have been rotated through approximately 90 degrees, the detent projections 140 snap into the other set of detent recesses 144. It is advantageous to make the insulator 66 from a resilient wear-resistant plastic such as nylon or Delrin.

It will be recognized that the electrical switch of the present invention is very ingenious and compact in its construction. It is also effective and dependable in operation. The detent action of the insulator considerably reduces the cost and complexity of the switch.

Various modifications, alternative constructions and equivalents may be employed without departing from the true spirit and scope of the invention, as exemplified in the foregoing description and defined in the following claims.

We claim: 1. In an electrical switch, the combination comprising a case having a bore therein, a carriage rotatably mounted in said bore, an insulator having body means mounted on said carriage, a contactor mounted on said insulator, contact means disposed in said case for engaging said contactor, flexible resilient longitudinal leg means formed in one piece with said insulator, first detent means on said leg means, and second detent means on said case for engaging said first detent means, said leg means resiliently biasing said first detent means into operative engagement with said second detent means, said insulator having longitudinal slot means formed therein between said body means and said leg means of said insulator and extending from one end thereof part way along said insulator toward the opposite end thereof. 2. In an electrical switch, the combination comprising a case having a bore therein, a carriage rotatably mounted in said bore, an insulator having body means mounted on said carriage, a contactor mounted on said insulator, contact means disposed in said case for engaging said contactor, a plurality of flexible resilient longitudinal leg means formed in one piece with said insulator, a plurality of first detent means on said leg means, and a plurality of second detent means on said case for engaging said first detent means, said leg means resiliently biasing said first detent means into operative engagement with said second detent means, said insulator having longitudinal slot means formed therein between said body means and said leg means of said insulator and extending from one end thereof part way along said insulator toward the opposite end thereof. 3. In an electrical switch, the combination comprising a case having a bore therein, a carriage rotatably mounted in said bore, said carriage having a transverse insulator slot therein, an insulator having body means slidably mounted in said insulator slot, a contactor mounted on said insulator, contact means disposed in said case for engaging said contactor, a pair of flexible resilient longitudinal leg means formed in one piece with said insulator, a pair of first detent means on said leg means, and a pair of second detent means on said case for engaging said first detent means, said leg means resiliently biasing said first detent means into operative engagement with said second detent means, said insulator having longitudinal slot means formed therein between said body means and said leg means 6 of said insulator and extending from one end thereof part way along said insulator toward the opposite end thereof.

4. In a key operated electrical switch,

the combination comprising a casing having a bore therein,

a carriage rotatably mounted in said bore,

said carriage having a forwardly opening key slot therein,

a tumbler slot extending transversely in said carriage and intersecting said key slot,

a tumbler slidably mounted in said tumbler slot,

a spring biasing said tumbler in one direction in said tumbler slot,

a transverse insulator slot formed in said carriage behind said tumbler slot,

an insulator having body means slidably received in said insulator slot,

a contactor mounted on the rear portion of said insulator,

a terminal board mounted in the rear end of said casing,

a plurality of contacts mounted on said terminal board for engagement by said contactor,

a spring disposed between said insulator and said con tactor and biasing said contactor for engagement with said contacts,

a pair of flexible resilient longitudinal leg means formed in one piece with said insulator,

a first pair of detent means on said leg means,

and a second pair of corresponding detent means on said casing for engaging said first detent means,

said leg means resiliently biasing said first detent means into operative engagement with said second detent means,

said insulator having a pair of spaced longitudinal slots formed therein between said leg means on said body means of said insulator and extending from one end thereof part way along said insulator toward the opposite end thereof.

5. In a key operated electrical switch,

the combination comprising a case having a bore therea carriage rotatably mounted in said bore,

said bore having a larger front portion and a relatively smaller rear portion,

said carriage having a larger front portion received in said front portion of said bore,

said carriage having a reduced rear portion received in said smaller rear portion of said bore,

a longitudinal key slot extending through said carriage,

a transverse slot formed in said carriage,

said transverse slot having a front portion intersecting Wit-h said key slot and extending through said larger front portion of said carriage,

a tumber slidably received in said front portion of said transvserse slot,

said transverse slot having a rear portion formed in the rear portion of said carriage,

an insulator mounted in said rear portion of said transverse slot,

the front of said insulator being slidably engaged with the rear of said tumbler,

a flange on the front portion of said insulator and received in the larger front portion of said bore for retaining said insulator and said tumber in said transverse slot in said carriage,

a plurality of stationary contacts disposed in said casing behind said insulator,

a contactor mounted on said insulator for sliding movement in a front to rear direction,

said contactor being engageable with said contacts,

a spring disposed between said contactor and said insulator for biasing said contactor rearwardly while biasing said insulator forwardly,

a plurality of flexible resilient longitudinal leg means formed in one piece with said insulator,

a plurality of first detent means on said leg means,

and a plurality of second detent means on said case for engaging said first detent means,

said leg means resiliently biasing said first detent means into operative engagement with said second detent means,

said insulator having longitudinal slot means formed therein between said body means and said leg means of said insulator and extending from one end thereof part way along said insulator toward the opposite end thereof.

6. In a key operated electrical switch,

the combination comprising a case having a bore therea carriage rotatably mounted in said bore,

said bore having a larger front portion and a relatively smaller rear portion,

said case having a shoulder between said larger front portion and said smaller rear portion of said bore,

said carriage having a larger front portion received in said front portion of said bore,

said carriage having a reduced rear portion received in said smaller rear portion of said bore,

a longitudinal key slot extending through said carriage,

said carriage having a transverse slot therein,

said transverse slot having a front portion intersecting with said key slot and extending through said larger front portion of said carriage,

a tumbler slidably received in said front portion of said transverse slot,

said transverse slot having a rear portion formed in and extending through the rear portion of said carrrage,

an insulator mounted in said rear portion of said transverse slot,

the front of said insulator being slidably engaged with the rear of said tumbler,

flange means on the front portion of said insulator and received in the larger front portion of said bore and against said shoulder for retaining said insulator and said tumbler in said transverse slot in said carriage,

a plurality of contacts disposed in said case behind said insulator,

and a contactor mounted on said insulator for engaging said contacts.

References Cited by the Examiner UNITED STATES PATENTS 1,945,562 2/1934 Norviel 200-44 2,542,967 2/1951 Waechter 287-58 2,630,502 3/1953 Hept 20044 2,949,692 8/1960 Kuhn 287-58 BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner. 

1. IN AN ELECTRICAL SWITCH, THE COMBINATION COMPIRISNG A CASE HAVING A BORE THEREIN, A CARRIAGE ROTATABLY MOUNTED IN SAID BORE, AN INSULATOR HAVING BODY MEANS MOUNTED ON SAID CARRIAGE, A CONTACTOR MOUNTED ON SAID INSULATOR, CONTACT MEANS DISPOSED IN SAID CASE FOR ENGAGING SAID CONTACTOR, FLEXIBLE RESILIENT LONGITUDINAL LEG MEANS FORMED IN ONE PIECE WITH SAID INSULATOR, FIRST DETENT MEANS ON SAID LEG MEANS, AND SECOND DETENT MEANS ON SAID CASE FOR ENGAGING SAID FIRST DETENT MEANS, 